Colec11 Knockout B16 Cell Line

The Colec11 Knockout B16 Cell Line is a CRISPR/Cas9-edited murine melanoma cell line in which the Colec11 gene has been disrupted to abrogate expression of collectin-11, a soluble C-type lectin that functions as a pattern recognition receptor. This knockout cell line is derived from the B16 parental line and is intended for loss-of-function studies investigating the lectin complement pathway in a tumorigenic melanoma background. CRISPR/Cas9-mediated gene disruption eliminates collectin-11 protein production, thereby preventing the recruitment of mannan-binding lectin-associated serine proteases (MASP-1 and MASP-2) and subsequent initiation of the complement cascade, without introducing specific modifications to the editing mechanism. Researchers can use this model to dissect the contribution of collectin-11 to complement activation, apoptotic cell clearance, and immune surveillance within the tumor microenvironment.

The parental B16 cell line is a C57BL/6 mouse-derived melanoma line that is extensively used in syngeneic mouse models for melanoma research. These cells are tumorigenic and retain key melanocytic features, making them a robust system for studying tumor growth, metastasis, and interactions with the host immune system. The B16 background provides a well-characterized platform for evaluating the role of innate immune sensors in cancer progression, as these cells form aggressive tumors in immunocompetent hosts and respond to immunological interventions. By engineering a Colec11 knockout in this line, scientists gain a powerful tool to examine how the loss of a single complement-initiating molecule alters tumor behavior and the surrounding immune landscape in a controlled in vitro and in vivo setting.

Collectin-11, encoded by Colec11, is a member of the collectin family of soluble pattern recognition receptors that bind to carbohydrate ligands on microbial pathogens and apoptotic cells. It forms complexes with MASP-1 and MASP-2, which are proteases that, upon ligand binding, cleave complement components C4 and C2 to generate the C3 convertase, thereby activating the lectin complement pathway. This leads to opsonization, release of anaphylatoxins C3a and C5a, and formation of the membrane attack complex. The gene is transcriptionally regulated by NF-??B and is upregulated in response to pro?inflammatory stimuli such as TNF?alpha, IL?1beta, and Toll?like receptor agonists. Downstream, collectin-11 signaling intersects with calreticulin-mediated phagocytosis and influences apoptotic cell clearance. The knockout of Colec11 disrupts this network, blocking MASP?2?dependent complement activation and reducing the deposition of complement fragments on target cells.

In the context of B16 melanoma, collectin-11 deficiency is expected to attenuate complement-mediated cytotoxicity and opsonophagocytosis, potentially enhancing tumor immune evasion. Because melanoma cells are often subjected to complement attack in the tumor microenvironment, loss of collectin-11 may shift the balance toward tumor survival by diminishing the clearance of apoptotic cancer cells and dampening local inflammation. This knockout line therefore serves as a valuable model for studying how tumors subvert innate immune recognition and for identifying complement-dependent mechanisms that influence metastasis and response to immunotherapy. Its syngeneic compatibility allows direct investigation in C57BL/6 mice without the confounding effects of xenograft rejection.

This Colec11 Knockout B16 Cell Line is suitable for a wide range of applications in tumor immunology and complement biology. Representative assays include western blotting and RT-qPCR to confirm knockout efficiency, immunofluorescence and flow cytometry to assess complement fragment deposition (e.g., C3b, C5b-9), and functional tests such as complement-mediated cytotoxicity assays, phagocytosis assays, and in vitro migration/invasion studies. In vivo, the line can be employed in syngeneic mouse tumor growth assays, experimental lung metastasis models, and complement-targeted therapeutic screening. It also facilitates exploration of innate immune evasion mechanisms and the role of the lectin pathway in melanoma progression. For further technical details, please contact Ascent Research.